European Union leaders decided to finance a disputed satellite navigation system at their Barcelona summit meeting over the weekend. The system, known as Galileo, would rival the Global Positioning System of the United States. The project is budgeted for $3 billion and is scheduled to be completed by 2008. Galileo had been stymied for several months by questions on the project's economic viability and opposition from the United States government. The Department of Defense has voiced concerns that Galileo would interfere with the functioning of Global Positioning System military signals. In a divisive vote in December, European transportation ministers refused to approve financing for Galileo, pushing the final vote to European Union leaders. The approval over the weekend is considered a victory for France, where scientific, political and business leaders have championed the project. The French president, Jacques Chirac, has said that Europe ''risked becoming vassals'' of the United States if it did not proceed with Galileo.